Automated data storage libraries provide access to data storage cartridges which are typically stored in storage shelves and accessed by a robot accessor having a picker configured to access and deliver data storage cartridges to and from storage shelves and one or more data storage drives. The robot accessor typically moves back and forth among the storage shelves and data storage drives, and positions the picker at the desired storage shelf or data storage drive. Communication is provided to the robot accessor, for example, as commands or signals to make the desired moves, or as address information so that a processor of the robot can determine the desired moves. Additionally, a detector may be mounted on the robot accessor or picker to read information from the shelves, markers within the library, and/or from labels on the data storage cartridges.
Communication with the robot accessor is typically made via a flexible cable which unwinds and winds in accordance with the movement of the robot accessor. The flexible cable has certain disadvantages including the possibility of breakage, difficulty in turning corners or crossing aisle intersections, and the need to replace the cable when the library is expanded. Other techniques include wireless radio and infrared communications. Radio poses security and interference risks, while infrared or other optical means can have interference and line-of-sight concerns.